Surgical tool for cutting graft skin



Jan. 15, 1952 H. H. STRYKER v2,582,511

SURGICAL Toor. FOR CUTTING CRAFT SKIN Filed June so, 195o IN V EN TOR.

@MMT

Patented Jan. 15, 1952 SURGICAL TOOL FOR CUTTING GRAFT SKIN Homer H. Stryker, Kalamazoo, Mich., assignor to Orthopedic Frame Company, Kalamazoo.

Mich.

Application June 3l), 1950, Serial No. 171,460

(Cl. 12S-305) 11 Claims.

This invention relates to improvements in surgical tool for cutting graft skin.

'I'he principal objects of this invention are:

First, to provide a surgical instrument for rapidly cutting regular and even strips of skin for graft purposes.

Second, to provide a power driven graft skin cutter in which the thickness of the graft skin is constantly regulated.

Third, to provide a cutter which is easily operated and which automatically leaves an even regular edge on the graft skin.

Fourth, to provide a cutting head for attachment to a power driven tool, which attachment can be sterilized along with other surgical instruments.

Fifth, to provide a graft skin cutter which has a guard functioning to stretch the skin to flat position for accurate and regular cutting of the graft.

Other objects and advantages relating to details of my invention will be apparent from a consideration of the following description and claims. The drawings, of which there is one sheet, illustrate a preferred form of my invention.

Fig. 1 is an elevational view partially broken away in vertical cross section of my instrument 1 in operative position.

Fig. 2 is an enlarged transverse vertical cross sectional view through the cutting head of my instrument taken along the plane of the line l2--2 in Fig. 3.

Fig. 3 is a bottom plan view of the instrument.

Fig. 4 is an enlarged horizontal cross sectional view through the driving mechanism for my cutter taken along the plane of the line 4--4 in Fig. 1. l

My cutter is designed to be mounted on the body and driven by the motor of the Plaster Cast Cutter disclosed in my Patent No. 2,427,580 issued September 16, 1947. in Fig. 1, the body of the instrument consists of a housing I' which encloses an electric motor adapted to be supplied with current through the cable 2. A neck 3 extends from-the body and forms a convenient grip for the instrument and also encloses a drive shaft 4. The lower end of the neck 3 has an enlarged recessed head or housing 5 formed thereon with the recess 6 opening to the lower end of the head. The drive shaft 4 projects into the recess and is provided With an eccentric l for driving the surgical tools mounted on the head. The head 5 also carries a vertically disposed bearing 8 laterally offset from the drive shaft 4 which coacts with my f As is generally illustrated graft skin cutting attachment as will be described presently.

My graft skin cutter which is applied to the above described instrument consists rst of a bearing plate 9 which is bolted to the head 5 by the bolts I0. The bearing plate 9 closes the recess 6 and has a tubular boss II formed on the underside thereof in alignment with the bearing 8 in the head. The boss II forms a bearing for the cutter shaft I2 which projects upwardly therefrom into the bearing 8 in the head.

Securedto the shaft I2 within the recess B as by the pin I3 is a crank arm I4 which projects across the recess 6 and has a slot or opening i5 formed therein for reception of the eccentric 1 on the drive shaft of the instrument. The throw of the eccentric is designed relative to the opening I5 to cause the crank arm and cutter shaft to oscillate rapidly through a relatively small angle as the drive shaft 4 of the instrument is rotated.

The lower end of the cutter shaft I2 below the boss II is enlarged to form a chuck end I6, and the chuck end and drive shaft are axially bored to receive the shank I'I of an arbor I8. A portion of the bore and arbor are noncircular in cross section as at I9, and a set screw 20 is provided for clamping. the arbor in the chuck. A shim 2 I, which may be of variable thickness, is positioned between the adjacent faces of the arbor and the chuck end of the cutter shaft.

The lower end of the arbor I8 is centrally bored and tapped as at 22 and has a thin annular shoulder 23 around the bore to center a cutting disk or blade 24 on the arbor. A beveled clamp washer 25 secured in place by the countersunk screw 26 secures the blade to the arbor. 'I'he blade is desirably formed of surgical steel and is highly sharpened around its periphery with the cutting edge thereof disposed upwardly. Only the leading or left edge of the blade actually cuts, but it is convenient to sharpen the blade all around its periphery so that it can be reversed before resharpening. 'I'he blade 24 is desirably circular for ease in sharpening but may be modified in outline so long as it retains a at disk-like shape with a convexly curved leading cutting edge.

Coacting with the cutting blade 24 is a guard structure consisting of a guard support plate 21 extending transversely of the head of the instrument. The bearing plate 9 carries a dependin g screw 28, and the guard support plate is secured to the underside of the bearing plate by a nut 29 threaded on the screw 28.` The lateral ends of the guard support plate 21 carry depending screws 33 which engage the annular guard ring 3l at their lower ends, Sleeves 32 positioned around the screws space the guard ring from the guard support plate so that the guard ring closely overlies the periphery of the blade 2t and projects radially therebeyond. It should be noted that changing the thickness of the shim 2! will vary the distance between the bottom of the guard ring 3| and the top of the blade 2li.

The underside of the guard ring 3i is upwardly and outwardly beveled completely therearound as at 33, and a depending rib 34 is formed on the underside of the guard ring to extend around the back of the blade to approximately the diametrically opposed sides of the blade, as is best illustrated in Figs. 1 and 3. The leading edges of the rib 3d curve smoothly upwardly to the underside of the guard ring as at 35 and function to engage and press down the iiesh below the rear portion of the blade as the instrument is advanced toward the left as viewed in Fig. 1.

in using the instrument the beveled under surface of the leading edge of the guard ring is first applied to the skin to be cut with the body I and neck t of the instrument in inclined position. The instrument is then moved forwardly and at the same time tilted backwardly so that the rib 34 depresses the portion of the skin behind the leading edge of the blade, which motion causes the leading edge of the blade to make a straight rectangular initial cut into the skin. The thick ness of the graft is of course controlled by the .'1

thickness of the opening between the blade and the guard ring. rIhe instrument can then be advanced to the left as far as is necessary during which motion the oscillating action of the blade will cleanly sever the graft skin while the guard rib stretches the skin tight and provides a raised surface in the skin along each side of the blade so that the side edges of the graft are straight and regular. The graft skin cut by the blade emerges upwardly within the guard ring as illustrated at 36 in Fig. 1. To remove the blade from the cut, it is merely necessary to tilt the body and neck rearwardly while finishing the cut so that the blade emerges from the skin in a smooth rectangular cut.

I have thus described a highly practical embodiment of my cutter so that others may reproduce and use the same with such minor modifications as may be desirable and which may fall within the scope of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A surgical instrument for cutting graft skin comprising, a main body enclosing an electric motor and having a head portion recessed on the lower end thereof, a drive shaft from said motor extending to said recess and having an eccentric positioned therein, a bearing plate secured to said head and closing said recess, a cutter shaft journaled in said bearing plate and said head in parallel eccentric relationship to said drive shaft, a crank arm secured to said cutter shaft within said recess and forming a slot within which said eccentric is received,A for oscillating said crank arm and cutter shaft, a chuck head formed on l e lower end of said cutter shaft, an arbor having a shank removably received in said chuck end and extending therebelow, a shim positioned between said arbor and said chuck end, a circular:I Quilting 4 blade secured to the lower end of said arbor nor mal to said cutter shaft and having a sharpened periphery, a guard support plate secured to the bottom side of said bearing plate and projecting laterally to each side thereof, a guard ring secured to said guard support plate in spaced relationship therewith to closely overlie the periphery of said .blade and project radially therebeyond, the

underside of said guard ring being upwardly and outwardly beveled, and a guard rib extending from the underside of said guard ring around the back of said blade and extending to the diametrically opposed sides of said blade, said guard rib projecting below the level. of the edge of said blade and terminating at its forward ends in upwardly curved skin depressing portions.

2. A surgical instrument for cutting graft skin comprising a main body enclosing an electric motor and having a head portion recessed on the lower end thereof, a drive shaft from said motor extending to said recess and having an eccentric positioned therein, a bearing plate secured across said recess, a cutter shaft journaled in bear lng plate in parallel eccentric relationship to said drive shaft, a crank arm secured to said cutter Shaft within said recess and forming a slot within which said eccentric is received for oscillating said crank arm and cutter shaft, a chuck head formed on the lower end of said cutter shaft, an arbor removably received in said chuck end and extending therebelow, a shim positioned between said arbor andsaid chuck end, a circular cutting blade secured to the lower end of said arbor normal to said cutter shaft and having a sharpened periph-x ery, a guard support plate secured to said head and projecting laterally to each side thereof, a guard ring secured to said guard support plate in spaced relationship therewith to closely overlie the periphery of said blade and project radially therebeyond, the underside of said guard ring' being upwardly and outwardly beveled, and a guard rib extending from the underside of said guard ring around the back of said blade and extending to opposed sides of said blade, said guard rib projecting below the edge of said blade and terminating at its forward ends in upwardly curved skin depressing portions.

3. A surgical instrument for cutting graft skin comprising a main body enclosing an electric motor and having a head portion recessed on the lower end thereof, a drive shaft from said motor extending to said recess and having an eccentric positioned therein, a bearing plate secured tc said head and below said recess, a cutter shaft journaled in said bearing plate in parallel eecentric relationship to said drive shaft, a crank arm secured to said cutter shaft within said recess -and forming a slot within which said eccentric is received for oscillating said crank arm and cutter shaft, an arbor removably received in the lower end of said cutter shaft and extending therebelow, a cutting blade secured to the lower end of said arbor and having a sharpened arcuate leading edge, a guard support secured to Said head and projecting laterally to each side thereof, a guard ring secured to said guard support in spaced relationship therewith to closely overlie the leading edge of said blade and project radially therebeyond, the underside of said guard ring being upwardly and outwardly beveled, and a guard rib extending from the underside of said guard ring along the opposed sides of said blade, said guard rib projecting below the level of the edge of said blade and terminating at its forward ends in skin depressing portions.

`4. A graft skin cutting attachment for a power driven surgical tool havingv al rotatable drive shaft with an eccentric projectingv therefrom comprising, a bearing `platea'ttachableto said tool adjacent to said eccentric and having a bearing formed therein parallel to 'and olset from the shaft in said tool, a cutter shaft journalcd in said bearing and projecting therebelow, a crank arm secured to said cutter shaft and having a slot formed therein receiving said eccentric for imparting oscillating motion to said cutter shaft, a flat blade secured to the lower end of said cutter shaft in normal relationship thereto and having an arcuate leading cutting edge, a guard support attachable to said tool through said bearing plate, a generally circular guard ring carried by said guard' support in closely spaced overlying relationship with the periphery of said blade, the under surface of vsaid guard ring being beveled upwardly and outwardly from said blade along the cutting edge thereof, and a guard rib formed on the underside of said guard ring and projecting below the level of said blade, said guard rib having upwardly curved leading edges positioned radially outwardly from the sides of the cutting edge of said blade, said rib extending between said leading edges rearwardly around the rear of said blade.

5. A graft skin cutting attachment for a power driven surgical tool having a rotatable drive shaft with an eccentric projecting therefrom comprising, a bearing plate attachable to said tool adjacent to said eccentric and having a bearing formed therein parallel to and offset from the shaft in said tool, a cutter shaft journaled in said bearing and projecting therebelcw, a crank arm secured to said cutter shaft and having a slot formed therein receiving said eccentric for imparting oscillating motion to said cutter shaft, a dat blade secured to the lower end of said cutter shaft in normal relationship thereto and having an arcuate leading cutting edge, a guard support attachable to said tool, an annular guard ring carried by said guard support in spaced overlying relationship with the cutting edge of said blade, the under surface of said guard ring being beveled upwardly and outwardly from said blade along the cutting edge thereof, and a guard rib on the underside of said guard ring and projecting below the level of said blade, said guard rib having upwardly curved leading edges positioned radially outwardly from the sides of the cutting edge of said blade, said rib extending between said leading edges rearwardly around the rear of said blade.

6. A graft skin cutting attachment for a power driven surgical tool having a rotatable shaft with an eccentric projecting therefrom comprising, a bearing element attachable to said tool adjacent to said eccentric and having a bearing formed therein parallel to the shaft in said tool, a cutter shaft journaled in said bearing and projecting therebelow, a crank arm secured to said cutter shaft and having a recess formed therein receiving said eccentric for imparting oscillating motion to said cutter shaft, a fiat blade secured to the lower end of said cutter shaft in normal relationship thereto and having a curved leading cutting edge, a guard support attachable to said tool, an annular guard ring carried by said guard support in spaced overlying relationship with the cutting edge of said blade, and a guard rib on the underside of said guard ring and projecting below the level of said blade, said guard rib having leading edges positioned radially outward- 6 1y from the sides or the cutting edge pf said blade, said rib extending from said leading edges rearwardly to depress the skin at the side and to the rear of said blade.

7. A surgical tool for cutting graft skin comprising, an annular guard ring having an upwardly and outwardly beveled under surface on one side thereof, said side forming the leading side of the guard, a circular cutting blade positioned in spaced relationship below said guard `ring and having a cutting edge positioned under the radially inner portion of said beveled under surface, a skin depressing rib projecting from the bottom of said guard ring to below the level of said blade and disposed radially Aoutwardly from the sides of said blade and extending rearwardly from the leading cutting portion of said blade around the rear thereof, means connecting said. guard ring and said -blade in adjustably variable vertically spaced relationship, and means for rapidly oscillating said blade angularly about an axis normal to the blade and positioned radially inwardly of the cutting edge of the blade.

8. A surgical tool for cutting graft skin comprising, an annular guard ring having an upwardly and outwardly beveled under surface on one side thereof, said side forming the leading side of the guard, a cutting blade positioned in spaced relationship below said guard ring and having an arcuate cutting edge positioned under the radially inner portion of said beveled under surface, a skin depressing rib projecting from the bottom said guard ring to below the level of said blade and disposed radially outwardly from the sides of said blade and extending rearwardly from the leading cutting portion of said blade. means connecting said guard ring and said blade in adjustably variable vertically spaced relationship, and means for rapidly oscillating said blade angularly about an axis normal to the blade and positioned radially inwardly of the cutting edge of the blade.

9. A surgical tool for cutting graft skin comprising, a body having an oscillatable shaft projecting therefrom, means in said body connected to said shaft to oscillate the same, a generally flat cutting blade secured to the end of said shaft and normal thereto, said blade having a portion of its periphery convexly curved and sharpened to form a leading cutting edge extending through about the axis of said shaft, a guard fixedly carried by said body and disposed in closely spaced relationship above said blade, said guard projecting outwardly beyond said cutting edge and having an upwardly and outwardly beveled under surface terminating over said cutting edge, said guard further having an opening formed therethrough and extending radially to adjacent the periphery of said blade and along said cutting edge, and a skin depressing rib located on the underside of said guard and projecting below the level of said blade, said rib extending from leading ends on each side of said blade rearwardly from said cutting edge and around the rear ci' said blade.

l0. A surgical tool for cutting graft skin comprising, a body having an oscillatable shaft projecting therefrom, means in said body connected to said shaft to oscillate the same, a generally flat cutting blade secured tc the end of said shaft and normal thereto, said blade having a portion of its periphery convexly curved and sharpened to form a leading cutting edge, a guard xedly carried by said body and disposed in closely spaced relationship above said blade, said guard atea-5 1 1 projecting outwardly beyond said cutting edge, said guard further having an opening formed therethrough and extending radially to adjacent said cutting edge, and a skin depressing rib located on the underside of said guard and projecting below the level of said blade, said rib extending from leading ends on each side of said blade rearwardly from said cutting edge and around the rear of said blade.

11. A surgical tool for cutting graft skin comprising, a body having an oscillatable shaft projecting therefrom, means in said body connected to said shaft to oscillate the same, a cutting blade secured to the end of said shaft and having a sharpened convex cutting edge disposed in a plane normal to said shaft, a guard xedly carried by said body, said guard extending radially outwardly from said cutting edge of said blade and having a concave inner edge disposed in closely spaced relationship above said cutting edge, and skin depressing rib portions xedly carried by said body and projecting below the level of said cutting edge and said guard, said rib portions extending concavely away from said concave inner edge of said guard from ends of the rib portions located on each side of said con- Vex cutting edge of said blade.

HOMER H. STRYKER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 194,794 Wightmas Sept. 4, 1877 1,550,342 Cogley Aug. 18, 1925 1,871,606 Haddad Aug. 16, 1932 2,427,580 Stryker Sept. 16, 1947 

